641709 has 8 divisors (see below), whose sum is σ = 950720. Its totient is φ = 427788.

The previous prime is 641701. The next prime is 641713. The reversal of 641709 is 907146.

It is not a de Polignac number, because 641709 - 2³ = 641701 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 23767 = 641709 / (6 + 4 + 1 + 7 + 0 + 9).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (641701) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11857 + ... + 11910.

It is an arithmetic number, because the mean of its divisors is an integer number (118840).

2⁶⁴¹⁷⁰⁹ is an apocalyptic number.

It is an amenable number.

641709 is a deficient number, since it is larger than the sum of its proper divisors (309011).

641709 is a wasteful number, since it uses less digits than its factorization.

641709 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23776 (or 23770 counting only the distinct ones).

The product of its (nonzero) digits is 1512, while the sum is 27.

The square root of 641709 is about 801.0674128936. The cubic root of 641709 is about 86.2540262771.

The spelling of 641709 in words is "six hundred forty-one thousand, seven hundred nine".